Assembly is straight forward. The Stand off is mounted on the saddle with the existing M4 screws.

The bearing block has it's bearings pressed in and the shaft inserted. Then it can be screwed to the standoff with two more M4 screws.

The motor is bolted to it's mount with M5 bolts and nuts, and the 24 tooth pully mounted.Then the mount is screwed to the bearing block. On mine the screws need to be just above center in the long holes. It will take a couple of iterations of mounting the 48 tooth pully and carrefully working the belt on till you get the optimal tension.

Once the belt is tensioned, the M8 nut can be used to preload the bearings. This nut needs to be secured with some loctite on it's threads as it is subject to vibration. A lock nut is also a good idea (the reason for 11mm of thread, I just haven't got a second nut yet). The set screw for the 48 tooth pully can then be tightened.

You will need to screw the two nuts on and then play around with shims to get the right thickness between the nuts and cross slide. You need to be able to get a fine screw driver down between the nuts, preloading and first tightening one, and then the other.